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NASA's X-Fleet
Spaceship
Today,
there are several new X-planes being developed, let's discuss three of
them:
- The X-37, which will test many space plane technologies,
including re-entry capabilities.
- The X-34, a suborbital vehicle that will test technologies
to reduce cost, time and personnel for space launches.
- The X-33, a reusable launch vehicle (RLV) that is
a prototype for a space shuttle replacement.
X-37
X-37 is the newest and fastest X-planes among the three mentioned above.
The X-37 will not be launched under its own power, but others will. It
is designed to be launched into space on a secondary vehicle. A unmanned,
programmable plane will ride onboard the space shuttle as a secondary
payload. When in orbit, the X-37 will be deployed from the shuttle's cargo
bay. It will then remain in orbit for 21 days, performing a number of
experiments before returning to Earth and landing like an airplane.
The X-37 is the only one of the two space planes that is designed to be
an orbital plane, and is able to travel at about 28,000 km/h.
The aim of the X-37 project is to test RLV technologies in harsh space
environments, and demonstrate about 40 advanced airframe, propulsion and
operations technologies. A main focus of the X-37 project is to improve
the thermal protection systems that keep spacecraft from burning up during
re-entry. The vehicle will be propelled by then AR-2/3 rocket engine,
which can produce more than 7,000 pounds of thrust. The AR-2/3 uses JP-10
jet fuel, which is a type of kerosene, and hydrogen peroxide as propellants.
Here are the facts of a X-37 plane:
Length - 8.38 m (27.5 feet)
Weight - 6 tons
Length of a wingspan - 4.57 m (15 feet)
Size of the experiment bay - 2.13 X 1.21 m (7 X 4 feet)
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X-34
X-34 is testing new technologies to build future spacecraft that will
low mission costs.
In 1999, NASA strapped the unmanned X-34 to the underbelly of an L-1011
carrier aircraft for a captive carry flight, in which the X-34 remained
attached to the L-1011 for the duration of the flight. During the test
flight, scientist were capable to analyzing several functions of the X-34,
including the release of rocket propellant into the engine and electrical
connections between the X-34 and the L-1011. Later, the X-34 will be dropped
from the L-1011 at an altitude of 40,000 feet, and glide unpowered down
to a runway landing. The X-34 space plane will be powered a Fastrac rocket
engine, which is built mostly from off-the-shelf components, and has fewer
parts than other rocket engines. The Fastrac rocket engine operates with
a single turbopump, which is composed of only two pumps -- one for kerosene
and one for liquid oxygen. The engine's gas generator cycles a small amount
of kerosene and oxygen to provide gas to drive the turbine, and then exhausts
the spent fuel.
Here are the facts of a X-34 plane:
Length - 17.6 m (58 feet)
Length of a wingspan - 8.53 m (28 feet)
Speed - 9012 kph (5600 mph)
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X-33
X-33 is the most expensive and the most ambitious of NASA's space planes.
The X-33 is a prototype for a unique single-stage-to-orbit vehicle. It's
wedge-like shape is unlike any spacecraft that has preceded it.
At its base, the width of the X-33 is longer than its length. The purpose
of the design is to allow the spacecraft to hold all of the needed propellant
onboard the ship, thus eliminating thr need for solid rocket boosters,
so the weight is much be reduced. The cost of launching a X-33 is expected
to be only a tenth of the cost of lauching the space shuttle.
The X-33 will be propelled by two uniquely designed engines. It is the
first space plane to use Linear Aerospike engines. The shape of the engines
is a better fit for the wedge-shaped X-33 than the conventional bell nozzle
rocket engines. The Aerospike nozzle is V-shaped, which is called a ramp,
is different from the nozzle of the Bell rocket engines. The hot gases
are shot from the chambers along the outside of the ramp's surface.
The ultimate goal of the X-33 prject is to produce a commercial aircraft
called the VentureStar, which will replace the space shuttle. The size
of the VentureStar will be about twice that of the X-33 prototype. Also,
the VentureStar will use the same type of engines and the same construction
materials. No only would the VentureStar be used to put payloads into
space, but it could also be used as a space tourism vehicle. The success
or failure of the X-33 will determine whether the VentureStar becomes
the vehicle that enables public access to space.
Here are the facts of a X-33 plane:
Length - 21 m (69 feet)
Width - 23.5 m (77 feet)
Speed (when using Linear Aerospike engines) - 14,645 kph (9,100 mph)
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